*4.2. Scheme of Optimizing Zoning*

The geographic grid could describe in detail the spatial heterogeneity of the PLEF, but there was also a problem in that it divided administrative units, which was not conducive to space governance [53,54]. Therefore, to ensure that the optimization results of the PLES have good practical significance, we used townships as the basic unit to optimize the space division and proposed suggestions for different development directions. First, based on the recognition result of the combination categories of PLES, we used the space superposition method to compare the areas of different space categories. Then, the adjacent or similar categories were merged according to the principle of ecological priority, area dominance and coordinated development (Table 6). Finally, the optimal zoning scheme of PLES is proposed, which takes the township as the basic unit (Figure 6).


**Table 6.** Optimized zoning of the PLES in Jiangjin District.

**Figure 6.** Optimized zoning map of the PLES of Jiangjin District in 2018.

(1) Comprehensive promotion zone. This area has ecological, living and ecological functions, and it mainly distributed in the east of the northwest area of Jiangjin District. The land use types in this area are dominated by paddy fields and dry land, with abundant cultivated land resources but a relative lack of infrastructure. Therefore, this area should make full use of regional resource endowments, vigorously develop high-efficiency agriculture such as flowers, seedlings, and high-quality fruits, establish small and medium-sized entrepreneurship bases, develop supporting industries and leisure tourism, promote the integrated development of agriculture and tourism, and enhance the production function. Second, it should strengthen the harmless treatment of domestic sewage and garbage and the control of agricultural nonpoint source pollution and soil pollution. In addition, protection measures of the ecological environment should be taken to improve the ecological function. Moreover, the construction of public infrastructure services should be strengthened, especially rural roads, medical health and education, to continuously improve the living environment and improve the quality of life.

(2) Ecological conservation zone. This area takes the ecological function as the main function, while living function and production function as the secondary function. The land use types are mainly woodland, grassland and waters. This area covers the Simian mountainous areas in the south of Jiangjin District, the Linfeng mountainous areas in the north of Jiangjin District, the Longmen mountainous areas in the east of Jiangjin District and the waters of the Yangtze River across the north region of Jiangjin District. Undoubtedly, this area bears the responsibility of ecological protection, so it should exploit the advantages of the ecological function and reasonably and appropriately develop ecotourism and ecoindustry by protecting the ecological environment. In the southern region, Zhongshan Town, Bolin Town, Caijia Town and other places could moderately develop ecological leisure vacation tourism, seize the advantage of selenium-rich, plant ecological seleniumrich agricultural and sideline products, vigorously cultivate new green kinetic energy and transform the advantages of ecological environment into advantages of green development. The northern region of Jiangjin District should strengthen the comprehensive management

of industrial and agricultural pollution prevention, shoreline protection and restoration and combat illegal fishing to strictly protect the ecological environment and biodiversity of the Yangtze River.

(3) The main production-living and ecological improvement zone. This area is dominated by production and living functions, with weak ecological functions. This area is the core growth pole of the economic development of Jiangjin District. The land use intensity is high, and the economy is relatively developed. However, there were some problems in this area, such as its dense population, production and life pollution, which pose a great threat to ecological security. Moreover, the vegetation coverage rate is low, and the ecological function is weak in this area. Therefore, the area should continue to improve public infrastructure, such as transportation and logistics, strengthen the management of industry and improve the quality of the living environment. By strengthening production and the living function, high-tech industries should be developed, ecological environment management should be strengthened, ecological land areas should be increased, the ecological function should be improved and the coordinated development of the PLEF should be promoted.

(4) The main production-ecological and living improvement zone. This area is characterized by strong production and ecological functions and a weak living function. The region is flat and rich in arable land resources. However, the infrastructure and public services are backward, and the living environment needs to be improved. By protecting arable land resources, this area should strengthen the construction of infrastructure, such as transportation, culture and sports centers, to improve life service functions. In addition, this area should strengthen the treatment of rural domestic garbage, livestock and poultry manure, improve the quality of human settlements and continuously improve regional life features.
